1. Field of the Invention
In electrical and electronic apparatus such as, although not necessarily exclusively, apparatus for receiving broadcast digital data, which apparatus is commonly referred to as a broadcast data receiver, personal video recorder or set-top box, there is a need to dissipate heat which is generated within the apparatus when the same is in use. The invention relates to electrical and electronic apparatus and the need to cool the same, and/or components therein, when in use, by allowing heat which is generated during use of the apparatus to be dissipated from the apparatus.
2. Prior Art
Conventionally, methods and means for dissipating heat which is generated within electrical apparatus, allow the cooling of the particular component within the apparatus which is creating the most heat but greater difficulty is experienced in removing the heat from within the outer housing of the apparatus and allowing the same to escape to the external environment. This can therefore cause a build up of heat within the housing and hence within the apparatus generally and this can, in certain circumstances, adversely affect the performance of the apparatus as a whole and/or specific components within the apparatus. The build up of excessive heat can also cause problems to the manufacturer if the level of the heat exceeds that which is specified by the end customer. In extreme situations the build up of heat can be such as to cause the apparatus to be a potential fire or damage hazard in the environment in which it is used, such as a domestic premises.
The above problem is further exacerbated by market trends to reduce the overall size of apparatus of this type so as to allow the same to be less obtrusive and hence regarded as more attractive for use at the location in the premises where the same is to be used. However, the reduction in size of the apparatus, combined with the higher core processor power of components used within the apparatus, means that in many cases, the limiting factor to the design of the electrical apparatus, and in particular the size of the same, is no longer the actual physical size of the components to be used in the apparatus but the ability of the apparatus to handle and dissipate the heat which is produced by the components within the space of the housing.
It is also known to be able to use electrical means such as fans to allow heat dissipation to be achieved but the noise and/or vibration of operation of these devices tends to be such as to cause the experience of using the apparatus to be adversely affected. For example if the apparatus is used to generate television and/or radio programs then the sound for the same can be masked or at least partially affected by the sound of operation of the cooling fan or fans of the apparatus.
There is therefore an accepted need to deal with the heat which is produced in order to keep the electronic components within the casing at a low enough temperature for the same to operate reliably and safely.
The aim of the present invention is to improve the efficiency of apparatus at transferring heat energy which is generated from components within the housing of an apparatus to the surrounding environment. A further aim is to provide apparatus which allows the heat to be dissipated by the use of means which do not create noise or vibration which can adversely effect the operation of the apparatus and/or prove to be irritating to users of the apparatus.
In a first aspect of the invention there is provided apparatus including a plurality of electrical and/or electronic components, at least one of which generates heat when in use and a housing which at least partially encloses said electrical and/or electronic components therein, characterised in that there is provided a heat dissipation means comprising a first portion located within the housing, which first portion is connected to or integral with a second portion located externally of the housing so as to allow the passage of heat from internally of the housing to externally of the housing via said portions of the heat dissipation means.
Typically the heat dissipation means is formed of a conductive material which allows the heat to be conducted from the first portion to the second portion.
In one embodiment, the first portion is directly contacted with at least one component within the housing which creates heat when in use and from
which heat is required to be dissipated. Alternatively, the said first portion is located adjacent to the vicinity of the said at least one component which creates heat in use. Yet further, the said first portion may be indirectly contacted with the at least one heat producing component via a further heat dissipation or heat transfer means such as, for example, a gel pad.
Typically the said first and second portions are formed integrally from a sheet material.
In one embodiment, the sheet material which is used is aluminium which, in one embodiment can be coated if required.
In one embodiment, the interface which connects the said first and second portions, passes through at least one aperture provided in the housing so as to allow the second portion to lie externally of the housing and the first portion to lie internally of the housing.
Typically, one of the first or second portions is provided in electrical contact with the housing so as to create a ground connection between the heat dissipation means and the housing.
In one embodiment, the heat dissipation means is mechanically located with the housing via one or a plurality of engagement means. In one embodiment, the engagement means connect the second portion to the housing and are located on said portion at one or more areas where the heat is known to be at its least when the apparatus is in use. This therefore minimises the possibility of heat transferring back to the housing from said second portion via the engagement means. In addition, or alternatively, the material of the housing and/or a coating applied to the housing, at least in the vicinity of the second portion and/or connecting portion, is provided of a form so as to reduce or minimise the opportunity for heat to pass from the second portion or connecting portion back to the housing.
In one embodiment, the second portion of the dissipation means is located in a recessed portion of the housing which leads to a recess in at least one of the faces of the housing so as to allow the escape of the heated air from the recess and hence into the external environment.
In one embodiment, the area of the second portion of the dissipation means is greater than the area of the first portion. However, it should be appreciated that the design dimensions and shape of the said first and second portions of the heat dissipation means can be selected to suit particular design requirements for a particular form of apparatus.
In one embodiment, the one or more components which are to be cooled are integrated circuits or chips which are located on a printed circuit board within the housing.
Typically the apparatus is provided with means to receive and process digital data to allow the generation of television and/or radio programs.
In a further aspect of the invention there is provided a heat dissipation means, said heat dissipation means comprising a first portion and a second portion connected to or formed integrally therewith, said first portion provided for location within a housing of electrical apparatus for location at or adjacent to one or more components from which heat is required to be dissipated when in use and wherein the second portion is provided for location externally of the housing of the electrical apparatus and heat is transferred to the second portion from the first portion, to be dissipated to the external environment.
In one embodiment, the first and second portions of the heat dissipation means, are formed in parallel, offset, planes.
In one embodiment, the said heat dissipating means is formed of sheet metal such as aluminium.
In one embodiment the heat dissipation means include an interface portion provided intermediate the first and second portions. Typically the interface portion and first and second portions are integrally formed.